In small bowl, mix all Herbed Lemon Oil ingredients. Cover and let stand at least 1 hour to blend flavors.
In 2-quart microwavable casserole, place sausages, water and onion. Cover and microwave on High 5 minutes; rearrange sausages. Re-cover and microwave on Medium (50%) 5 to 7 minutes or until sausages are no longer pink in center. Remove sausages; discard onion and water.
Brush grill rack with vegetable oil. Heat coals or gas grill for direct heat. Brush all sides of chicken, beef and sausages with oil mixture.
Grill meats uncovered over medium heat, brushing frequently with oil mixture and turning occasionally, for the following times: Grill beef 5 minutes. Add chicken and continue grilling. Grill beef 12 to 16 minutes or to desired doneness. Grill chicken 15 to 20 minutes or until juice is clear when center of thickest part is cut (170°). Add cooked sausages during the last 5 to 10 minutes of girlling to brown.